Iftheweatherhadbeenbetter,wecouldhavehadapicnic.Butit

问题详情：

If the weather had been better, we could have had a picnic. But it ____ all day.

A. rained                    B. rains                   C. has rained               D. is raining

【回答】

A

解析从题干前部分句子的谓语动词结构（虚拟语气）可以看出是指过去某个时间已经下了整天的雨。所以应该用一般过去时态。该题解题关键要从题干前部分入手。if非真实条件句用的过去完成时，主句用would have done，我们可以看出这是与过去事实相反的虚拟语气。

知识点：一般过去时及其被动式

题型：选择题